Nykyautoissa vika ilmenee usein vain valon syttymisenä kojelaudassa. Vian paikantaminen edellyttää yleensä huoltoon viemistä ja vikakoodien lukua. Nyt tähän OBD-vikadiagnostiikkaan on tulossa uusi standardi.

OBD (eli On-board diagnostics) on monen mielessä synonyymi ajoneuvojen vikakoodien luvulle, mutta tässä on ollut käytössä neljä eri standardia. SAE:llä on kaksi eri OBD-standardia ja ISO on määritellyt eurooppalaiseen käyttöön kaksi standardia. Onneksi standardit ovat hyvin lähellä toisiaan.

SAE:n uusin standardi on nimeltään J1979-2 (OBD on UDS), joka julkistettiin huhtikuussa 2021. Nyt valmistumassa on SAE J1979-3 eli ZEV on UDS). Se määrittelee speksit vähäpäästöisten (Zero Emission Vehicles) ajoneuvojen diagnostiikkamittaukselle ja laitteille.

Käytännössä uusi standardi tuo huollon tai katsastuksen käyttöön sähköautoille ja pistokehybridiautoille räätälöidyn OBD-diagnostiikan. Käyttöön se on tulossa jo tänä vuonna ja Yhdysvalloissa kaikkien vähäpäästöisten autojen on tuettava uutta standardia vuodesta 2028 alkaen.

Last week my old Volvo suddenly stopped in the middle of a street in the city. Not a pleasant situation. Even worse! It showed an error message, and I could no longer start the engine anymore. I had to push it to the sidewalk and call my brother, a trained mechanic. The problem was smaller than I thought, and it can happen to you, too. Maybe you want to accompany me on my trip to prevent such things from happening again?

Yet another of these universal OBD (On Board Diagnostic) port engine remappers that claim to analyse your driving and then rewrite key parameters in your ECU (Engine/Electronic Control Unit) to offer greater power with less fuel.
I bought this one because it showed a picture of the PCB in the listing, showing that it uses an eight pin microcontroller and appears to have actual connections to the canbus network on the OBD port.

In standby the module enters a passive mode at 9mA where it pulses the communication LED. When activity is detected on the canbus network it directly affects the green LED and after a short time triggers the power LED to come on and the communication LED to start flickering. If the canbus becomes inactive the unit goes into standby mode after about a minute.
Because the chip has a direct connection to the canbus network it is possible for a malfunction to take out the network in your vehicle and cause lots of random problems when the other devices on that network are unable to respond to the ECU.
The unit is fake. It’s a placebo. To store suitable details for every single car since 1996 it would need to be able to identify models if it could read the VIN (Vehicle Identification Number) code and then have a database of parameters that could be adjusted with a suitable tuning algorithm for every model. That’s not viable for a little 8 pin chip and most cars don’t have the facility to make significant changes to the ECU tuning settings via the OBD port.

Turn your car into a ROCKET with this amazing device that reprograms your ECU for maximum torque while reducing fuel consumption. But only if you have a vivid imagination.
I actually love quack stuff like this. It’s probably come from the same factories that made the clone ELM 327 diagnostic units, but have now turned their attention to the much more profitable bogus OBD tuners. The component cost is very low and the construction can be done on one thin single sided PCB.

Their operation is as follows. The 12V supply at the OBD2 port is used to derive a 5V supply to power a low cost microcontroller. The unit fakes communication with the cars ECU by flashing and then flickering the LEDs like an OBD2 diagnostic unit. In reality no communication is taking place because the unit is not capable of changing the state of the car’s low impedance networks. Instead it just senses activity on them (if it even does that) to control LED activity. It’s possible that the only reason the network pins are involved at all is to make the unit look plausible to an untrained eye.

Although some cars can have some parameters changed via the OBD2 (On Board Diagnostics) port for easy dealer tweaks and the more extreme geeky re-tune garages, the concept of a single tiny device that can determine the brand, model, engine type and any subsequent manufacturer updates, then look up a chart with settings and limits and then somehow adjust the settings for efficiency based on the drivers style is somewhat debatable.

Our project is a black box – OPD-Pi using Raspberry Pi.

In this tutorial, you will learn how to connect your Raspberry Pi to a Bluetooth OBD-II adapter and display real-time engine data to your car’s aftermarket head unit!